How to truncate/round-off decimal numbers?

[jean-michel bain-cornu]

> just a thought: if you *always* work with "floats" with two decimals,
> you are in fact working with integers, but you represent them as a
> floats - confusing for the internal representation.
> 
> So why not work with int(float * 100) instead? This way you only have
> to take care of roundoffs etc when dividing.
And why won't you work with decimal module ?